hose

I bought a GT with no power steering and no power brakes. Thanks to the misguided suggestion of the seller, I have replaced the whole Hydroboost system before finding out it was just the power steering pump. I believe it broke because of a leak that had started where the hose connects to the...

Does anybody know what this vacuum hose goes to (it just disappears in the fender) and if it is mission critical? It comes in to a port right behind the throttle body. The hose is pretty old and porous. I'm on the hunt for vacuum leaks and I'd like to unplug it to test if this is the culprit...